<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
<script>
//    var str="aaaaDDVFGBGFBFasdd";
//    alert(str.toUpperCase().indexOf("DDV",0))
    var str="https://www.baidu.com/s?HmznHb3P1n4n0K15H-HFAILILF0";
    alert(str.indexOf("?",0))
</script>
</body>
</html>